1. Field
Example embodiments relate to ferrocene-containing polymers and organic memory devices using the polymers. Other example embodiments relate to ferrocene-containing polymers in which ferrocene is conjugated to the backbone of conductive conjugated polymers, and organic memory devices including the ferrocene-containing polymers.
2. Description of the Related Art
With the recent dramatic developments in digital communication technology, demand for a variety of memory devices has been increasing rapidly. Memory devices suitable for use in applications including, for example, portable computers and electronic devices, including mobile terminals, smart cards, electronic money, digital cameras, personal digital assistants (PDAs), digital audio players and/or multimedia players, are required for retaining data in memory even when no power is being applied to the memory device, thereby tending to reduce the memory-related power consumption of the device.
Conventional memory devices may include a bistable element that may be switched between a higher resistance state and a lower resistance state when a voltage is applied to the devices. Resistive memory devices are memories whose resistance is varied depending on an applied voltage and in which data is stored in response to changes in the resistance.
Chalcogenide materials, semiconductors and various types of oxides and nitrides are known to have resistive memory properties. Some organic materials are also found to have resistive memory properties. Of these resistive memory devices, organic memory devices may include an upper electrode, a lower electrode and a memory layer between the upper and lower electrodes, wherein the memory layer may be formed of an organic material and memory properties are realized by using bistability of resistance values obtained when a voltage is applied between the upper and lower electrodes. Next-generation organic memory devices ensure non-volatility, which is an advantage of conventional flash memories, and at the same time, overcome the disadvantages of undesirable processability, increased fabrication costs and decreased degree of integration.
Research has been done on various materials due to their potential use as materials for organic active layers of organic memory devices. One example of such an organic memory device utilizes an organic memory device including an upper electrode, a lower electrode and a selectively conductive media between the two electrodes wherein the selectively conductive media contains an organic layer and a passive layer and the organic layer is made of a conjugated organic material. Another example includes a molecular memory cell including a first electrode, a second electrode, and first and second charge storage molecules between the first and second electrodes and coupled to the electrodes by a molecular linkage. Other work has suggested a conductive polymeric composite for use as an electrode material of a secondary battery, the polymeric composite including a salt of a ferrocene derivative and a polypyrrole or its derivative.
Ferrocene and its derivatives are currently being investigated for their inherent electrical, optical and magnetic properties. However, a major portion of research on ferrocenes and its derivatives has been devoted to their use as fuel additives and polymerization catalysts. There hasn't been any research on the use of ferrocenes and its derivatives as materials for active layers of organic memory devices.